(19)
(11) EP 0 350 768 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
27.02.1991 Bulletin 1991/09

(43) Date of publication A2:
17.01.1990 Bulletin 1990/03

(21) Application number: 89112179.0

(22) Date of filing: 04.07.1989
(51) International Patent Classification (IPC)5: G01N 15/02
(84) Designated Contracting States:
DE FR GB

(30) Priority: 11.07.1988 US 217337

(71) Applicant: PACIFIC SCIENTIFIC COMPANY
Newport Beach California 92658 (US)

(72) Inventor:
  • Sommer, Holger T.
    Apartment 304 Greenbelt Maryland 20770 (US)

(74) Representative: Glaeser, Joachim, Dipl.-Ing. et al
Patentanwalt Königstrasse 28
D-22767 Hamburg
D-22767 Hamburg (DE)


(56) References cited: : 
   
       


    (54) Particle size measuring instrument with direct scattered light detection


    (57) In an instrument for measuring the size of particles entrained in a fluid stream, photodetectors are mounted on the walls of tubing shaping the flow of the fluid stream through a laser beam. The photodetectors generate electric current pulses in response to scattering of the light which is generated by the particles passing through the laser beam. The pulses generated by the photodetectors provide a measurement of particle size. The photodetectors are mounted either adjacent to the laser beam on the tubing walls or, alternatively, the tubing walls are mirrored above and below the laser beam and the photodetectors are mounted on the tubing walls at right angle bends of the tubing to receive the light reflected from the mirrored surfaces.







    Search report